Maria van der Hoeven said that although prices had eased somewhat in recent weeks, the threat of heightened political tension over Iran, limited spare production capacity, and unplanned supply outages remained.

"Prices remain very high," she told a conference in Australia. "High prices pose a real threat to the economic recovery."

Brent crude oil spiked to above $120 a barrel in the early part of 2012 but was trading yesterday at about $110 a barrel. That was the lowest since January, but still very high by historical standards.